Jilly, "soilless medium " is commercially packaged potting mix. These are usually peat based and include such amendments as perlite and vermiculite. My soilless medium of choice is bark based, with peat and perlite added. It's called "soilless " because this type of mix does not contain the sand, silt or clay which are components of (outdoor) soil. Soilless media, as a rule, maintain their porous structure for a long period of time. Porosity is the most important characteristic of a successful potting mix. 'Dead' refers, I presume, to the fact that these mixes are not teeming with the microorganisms found in an outdoor soil.....essential for a healthy soil system IN THE GROUND but wholly unnecessary in a potting medium. We don't need microorganisms in a potting mix to convert nitrogen. Period! Your soluble fertilizer of choice is ready to go. Stick with a fertilizer that you are comfortable with or already have. It should be one formulated for container plants....and does not matter what kind (usually) . The link provided by bugbite is for field grown marigolds. That has nothing to do with container culture.....nothing. You can use an 'all purpose ' fertilizer....same kind as for your other plants. The comparison between in-ground and container growing just does not work, for many reasons. For your ease of mind....the need for a high Potassium (middle number) number is largely a figment of the fertilizer companies. Just avoid too much nitrogen, which will promote an excess of vegetative growth at the sacrifice of flower production. Ken...I apologize to you for my earlier comment. I was wrong. For some reason, I focused in on the slow release comments (I like SRFs) and not the rest of your excellent advice. Conservative but regular applications of a soluble product is my usual routine, too. I hope you'll forgive me. This post was edited by rhizo_1 on Mon, Jun 24, 13 at 6:18

One important step to do that will help prevent fertilizer burn is to water your roses at least 3 hrs but not more than 24 hrs before you apply fertilizer & than water your roses a second time immediately after applying the fertilizer. This is extremely important to do with inorganic chemical fertilizers because many of them have properties similar to salt & this is why they are the fertilizer most likely to cause chemical burn. Many of the fertilizers you talked about are organic & are less likely to burn but I would still do this double watering because they are very dry & you need to get them wet so the soil microbes can start breaking them down & realeasing their nutrients to your roses. One last thing, I suggest that you have a soil test done to see what you really need to add to your soil. For example, you are talking about using Epsom salts & this is commonly recommended by many rose growers for the Mg but I don't use it because my soils have adequate to high levels of Mg & maybe your soils have enough Mg also but you won't know until you test your soil.

The main reason is that your plants are new. They want, no, they NEED to grow roots to grow canes and leaves in order to support beautiful blooms. The whole NPK complex supports this growth, don't get all tied up in needing more P or K. There is usually too much of those two. While I like MEF, I also prefer using some dry organic or organic-based fertilizer such as Espoma Rose-tone (or Holly-tone), Mills Magic Mix, Dr, Earth or whatever you can find locally. These help to condition the soil in addition to fertilizing. How often are you applying the fertilizer?

Nancy - Your experience is interesting. I think it depends on the cultivar. I also can't resist seeing the blooms. On some plants I've let bloom, there doesn't seem to be any impact. And others have very few buds or don't scape at all the following year. Karol Emmerich advised me to cut the scapes off hers that I received last September. She said it was best to let the plants put all their energy into growing roots. I like to fertilize my plants a bit in the fall with either compost or Milorganite. When I have fertilized in the fall and spring, I get the largest bud counts. Debra